Grasshoppers are members of the phylum Arthropoda. Grasshoppers belong to the phylum
arthropods and to the class insects. There are more than 900,000 species of insects.
They are mainly land animals and occupy almost every environment on land. The
development of wings gave grasshoppers advantages over other land invertebrates. They
could spread out into new areas, they could search larger areas for food, and they were
able to fly away and escape from predators.

Grasshoppers have an exoskeleton composed of chitin.
They have three pairs of jointed legs. The front pair are used for walking,
climbing, and holding food. The middle pair are used for walking and climbing.
The back pair of legs are used for jumping. There are three distinct body regions,
the head, the thorax, and abdomen. The head is used for eating and sensing, the
thorax is used for

movement, and the abdomen has the digestive and reproductive
organs. Two pairs of wings are attached to the thorax. Grasshoppers have one pair of
antennae that is used for sensing, one pair of large compound eyes that detect
movement, and three simple eyes that detect light and dark. Tympanum, or eardrums, on the
thorax are used for hearing. The grasshopper's spiracles and air tubes provide a way
for getting oxygen into the body and removing waste gasses from the body.
Grasshoppers lay a large number of eggs, and the eggs hatch very quickly.
This allows the grasshopper population to increase rapidly.

Part A Outside Observation

1. Locate the head, thorax, and abdomen.

2. Observe the head. Locate the two compound eyes and
the three simple eyes.

3. Identify the mouth parts. Use your magnifying glass to
locate:

Labrum: hinged upper lip that holds
food

Mandibles: crushing jaws

Maxillae: chew and taste food

Labium: hold food while being
chewed

4. Locate the typamum, or eardrums, on the thorax.

5. All insects have six legs. Locate:

Front Legs Middle Legs
Back Legs

6. Locate the two pairs of wings.

7. Find the tiny openings along the abdomen called
spiracles.
These are the breathing pores through which oxygen enters and carbon
dioxide leaves.

8. A female grasshopper has a much longer abdomen than a
male.
It ends in a four-pointed tip called an ovipositor through which eggs
are laid.

Grasshopper Dissection
and Internal Observation

The grasshopper's digestive tract is specialized to eat
plant tissue. The mouth parts hold, crush, and chew the food before it passes
into the mouth. From the mouth the food passes through the esophagus into the crop.
The food is stored in the crop. Next, food moves into the gizzard, where
teeth made of chitin grind it up further. Food then moves into the intestines where
glands digest the food. and other structures absorb the digested food. Undigested
food then goes to storage in the rectum, and then is eliminated out the anus.

Part B Internal structure

9. Remove the three right legs.

10.

Insert
the point of your scissors under the top surface of the last segment of the abdomen and
make a cut to the right of the mid-dorsal line all the way to the head. Be careful not to
cut the organs underneath.

11.

In
front of the thorax, cut down
the right side to the bottom of the grasshopper.

Cut
down between the next to the last and last abdominal segments.

12. Remove the exoskeleton from the right side of your grasshopper.

13. Locate the large dorsal blood vessel that runs down the
grasshopper's body.

14. Remove ovaries from the grasshopper. These look like maggots or brown rice.
Eggs are produced in the ovaries.